1. Field
Some embodiments of the invention relate to communications networks and, particularly, to wireless communications networks, such as the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN) Long Term Evolution (LTE) and Evolved UTRAN (E-UTRAN).
2. Description of the Related Art
A Universal Mobile Telecommunications System (UMTS) network includes three interacting domains: Core Network (CN), UMTS Terrestrial Radio Access Network (UTRAN) and User Equipment (UE). A main function of the CN is to provide switching, routing and transit for user traffic. The CN may also contain the databases and network management functions.
UTRAN includes base stations, or Node-Bs (NBs), and radio network controllers (RNC). UTRAN allows for connectivity between the UE and the CN. The RNC provides control functionalities for one or more Node Bs. The RNC and its corresponding Node Bs (NBs) are called the Radio Network Subsystem (RNS).
Long Term Evolution (LTE) refers to improvements of the UMTS through improved efficiency and services, lower costs, and use of new spectrum opportunities. In particular, LTE is a 3rd Generation Partnership Project (3GPP) standard that provides for an uplink speed of up to 50 megabits per second (Mbps) and a downlink speed of up to 100 Mbps. As mentioned above, LTE is also expected to improve spectral efficiency in 3G networks, allowing carriers to provide more data and voice services over a given bandwidth. Therefore, LTE is designed to fulfill future needs for high-speed data and media transport in addition to high-capacity voice support.